1. Field of the Invention
The present invention relates to composite materials having breathable barrier applications and particularly useful as a component of fasteners of the hook and loop type typified by those extensively marketed by VELCRO INTERNATIONAL and now available from numerous sources for applications from shoe ties to golf gloves and many others where nonpermanent attachment is desired. These fasteners fundamentally include a hook member and a loop member that, when pressed together, entangle in a manner that resists shear forces but can be separated when subjected to a desired level of peel force. The design of these members has become quite sophisticated and provides a wide range of properties obtainable by varying factors such as hook shape, size and flexibility as well as similar loop features. For many low cost applications such as fasteners for disposable garment applications like diapers and adult incontinent wear, it has been necessary to develop inexpensive manufacturing techniques and materials for such fasteners that, nevertheless, meet the performance requirements. Particularly for such applications where the loop component also serves as the backing material, it is highly desirable that it be both breathable for comfort and serve as a barrier to prevent leakage. The present invention provides an ideal loop fastener component particularly suited to such disposable product applications.
2. Background
The art is replete with references to hook and loop type fasteners and components for such fasteners intended for use in disposable product applications such as disposable diapers and the like. Just by way of example, reference may be had to coassigned U.S. Pat. No. 5,614,281 to Jackson et al. which, itself, provides much background information and for that purpose is incorporated herein by reference in its entirety. Other loop fastener materials are described in, for example, U.S. Pat. No. 4,761,318 to Ott et al., U.S. Pat. No. 5,032,122 to Noel et al., U.S. Pat. No. 5,326,612 to Goulait, U.S. Pat. No. 5,595,567 to King et al, and U.S. Pat. No. 5,647,864 to Allen et al. Briefly, a particularly economical loop component may be formed using nonwoven manufacturing techniques such as spunbonded processes that result in significant areas of the web between bond points where the filaments are unbonded to each other and available to engage hooks of a complementary hook member. Factors, such as configuration, number and area coverage of the bonds in the nonwoven as well as the selection of a particular hook member, may be varied to achieve a desired level of peel strength and other properties within a designated cost range. In addition, the selection of a polymer or other compositional ingredient for the nonwoven and/or the hook component can affect the performance and/or cost of the fastener in a given application. There remains a need for a loop fastener component that can have tailored properties such as peel strength, shear strength and refastenability as well as breathable barrier functions at a cost consistent with use as a backing component of disposable products. Other uses for breathable barrier materials having clothlike attributes such as surgical gowns and drapes, for example, will be apparent to those skilled in the art.